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The hydrodynamics of spherical capsules
Author(s) -
Ellis H. S.,
Kruyer Jan,
Roehl A. A.
Publication year - 1975
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450530124
Subject(s) - spheres , pressure gradient , mechanics , viscosity , materials science , solid body , shear (geology) , physics , composite material , astronomy
With water as the conveying liquid the pressure gradient of a train of spheres is comprised of a basic pressure gradient due to shear of the surrounding liquid, to which has to be added a very small density‐dependent increment due to solid friction, and a further increment due to any irregularity of the spheres. With viscous liquids the pressure gradient generally rises rapidly with specific gravity and with increase of viscosity. Even at the low specific gravity of 1.25 the power require‐nients of cast spheres conveyed by water are generally lower than those of smooth cylinders, and the advantage increases with increase of specific gravity. However, the lower power require‐uient has to be weighed against the possibly greater cost of forming spheres, and the cost of larger pipe that would be neces‐sary to secure a given throughput, particularly if the spheres were run at low velocities to secure very low pressure gradients.